DIY 5k Monitor - success :-)

[PaulD-UK]

@mmyk "...what is the general consensus for JRY SA1/FA1/AA1 board builds regarding cooling?"

If you put a 50 watt incandescent light bulb inside a sealed iMac case it will get quite hot after a while...
But, it won't be a problem as the aluminium case will dissipate this heat, so it won't rise to dangerous levels...

...for a light bulb, which is designed to run its filament at over 2000º...

The heatsink of the JRY--SA1 is designed to be fitted vertically against the back case ventilation slots above and below it.
This give adequate airflow over the heatsink fins.

In an iMac conversion, there is space for an internal airflow, but the air will heat up if it is trapped inside.
It doesn't seem to heat up too much so it kills the boards, because of the aluminium case, but it's anyone's guess if this actually shortens the life of the boards?

Allowing airflow over the rear of the board is definitely a good idea, and I'm doubtful if attaching a board directly against a 3D printed backing plate can be a good thing. 😱

Experience has shown that in practice the amount of airflow needed is actually very low, far less than the original iMac fan provides unless it is slowed right down.

I personally used the smaller fan from a 21.5" A1418 iMac, running at its slowest setting using a 4 wire PWM controller.
But most people don't seem to bother.....

 

[alexey-xxx]

@alexey-xxx
The JRY boards seem to work fine on 12V, the only thing that requires 24V is USB-C PD to power a laptop.

Strange behaviour of the Colour Mode. Does the 10 bit problem occur if you deactivate Better Display?
The other possible check to try to resolve this is to use a USB-C to DP 1.4 8K cable so you are using the DP input.
That usually gives the best performance with all these boards.
You could also try to power the board at 24V, to see if that improves 10 bit colour.

Monitor Control and Better Display are both controlling the display's audio volume in the same way at the same time.
I'm just using BD and it does both brightness and volume, very effectively.
But the volume setting on the Control Strip is also involved, so I keep that at the same setting so as to not have any effect.
Does disabling MC improve the audio, and give you volume control?

The amplifier chip used by JRY for the FA1 and SA1 boards probably has a high (up to ~10% THD) distortion at the levels needed in a monitor...

I tried a cheap amplifier board, but found the R1811 has (much) better sound.
I'm dubious of Chinese amplifier boards that are being sold at a price cheaper than Texas Instruments sell the audio amp chip that the amplifiers say they use....
The XH-A232 might work, I have no direct experience.

Yes, as soon as the 24V power supply arrives, I'll try it and report back. Switching off Better Display doesn't help. Through the DP 1.4 8K cable - goes default 8 bit and no such problems.

Monitor Control doesn't see the sound at all and doesn't adjust it in any way. When you press the volume keys - crossed out speaker.

Would it make sense to take a simple audio card and connect it via USB and connect the speakers to it? In this case the volume keys will work? I need the function of volume control from the keyboard.

 

[PaulD-UK]

The JRY—AA1 doesn’t have firmware that allows DDC keyboard volume control.
Maybe the SA1 is the same?

I don’t think anyone has reported fully on controlling the board’s audio, although someone else said it was ‘not good’.
A separate amp connected by USB should work fine.

@Ozpyn got audio volume control working with Windows, so that sounds like there should be some way to control it…

 

[alexey-xxx]

В JRY — AA1 нет прошивки, позволяющей регулировать громкость кнопок DDC.
Может быть, SA1 такой же?

Я не думаю, что кто-либо полностью отчитался о контроле звуковой платы, кто-то другой сказал, что он «не очень хорош».
Отдельный усилитель, подключенный через USB, должен работать нормально.

are there any examples of such audio cards with an amplifier? What kind of power should I look for? Or is a simple USB audio card and + XH-A232 enough?

Another question, if you connect the XH-A232 power supply to a common power supply, do you need to shield/isolate the power supply (I don't know the correct name).

 

[PaulD-UK]

USB input is usually done with a DAC that provides an analogue audio output to connect to the input of the main amp.

If the amp doesn’t have power supply input smoothing, then you may have to add a smoothing capacitor to get rid of noise from the PSU.